This invention relates generally to vehicle fuel pumps of the submerged type and particularly to peripheral pumps containing vaned rotating impellers adapted to be driven by electric motors.
Electrically driven submergible fuel pumps designed for operation in the vehicle fuel tank are well known for their decreased tendency to produce vapor lock, their dependability and the flexibility of a separate switchable power source, which enables engine operation to be automatically stopped in situations where great engine damage is threatened, such as loss of oil pressure. Of course, these advantages are not without their price; since the electric motor of such a pump is an additional element added to the vehicle fuel system which may occasionally fail.
Although the failure rate of such pumps has been quite low, improvements in the dependability or expected life of vehicle fuel pumps are always welcome, since the result of a failed vehicle fuel pump is generally an inoperable vehicle.
A more efficient fuel pump -- that is, a pump that produces a greater fluid output flow at a given rotational speed -- could be run at a lower speed, thus reducing wear in the pump and the electric motor for longer pump life and more dependable operation.